1. Field of the Invention
The present invention relates to an ink jet recording apparatus, an ink guide member in the inkjet recording apparatus, a suction cap engaged with the ink guide member, and a purge unit having the suction cap.
2. Description of the Related Art
Conventionally, there is known an inkjet recording apparatus that jets out ink from an inkjet head to thereby conduct printing. A large number of nozzles for jetting ink are formed in the inkjet head. Due to bubbles or dust entering the inside of a nozzle or due to the viscosity of the ink increased by evaporation of an ink solvent, there is a case in which the ink is not jetted from the nozzle or the jetting state of the ink is not suitable for recording. Therefore, an ink jet recovery process is carried out to remove such factors in failure in ink jet.
As a unit for carrying out such an ink jet recovery process, there is provided a unit including a cap capable of covering the nozzle opening surface of the inkjet head and a suction pump communicating with the cap and making suction power act thereon. The suction pump is driven in the state where the nozzle opening surface has been covered with the cap. Thus, ink is discharged from the nozzles forcibly so that the factors in failure in ink jet are removed together with the ink.
After the cap is released from the covering state, the ink received by the cap in the ink jet recovery process is discharged from the cap by the effect of suction power applied again, and introduced into a waste ink tank through the suction pump. In this situation, due to the improper configuration of the cap or the like, the received ink that cannot be discharged perfectly from the cap may remain therein.
When the ink remains in the cap, the ink may leak into the apparatus for some reason, or the ink may be solidified in the cap to thereby deteriorate the cap performance conspicuously. Further, the nozzle opening surface may be covered with the cap while recording is not conducted. When the cap serves as a conservative cap in such a manner, residual ink adheres to the nozzle opening surface when the nozzle opening is covered with the cap. Thus, there may occur a failure in ink jet such that the direction of ink jet from the nozzles is shifted from a predetermined direction.
To solve such problems, the shape of the cap has been hitherto devised. FIG. 35 is a longitudinal sectional view showing an example of a cap in the related art. The bottom surface of a concave portion 80a of a cap 80 is formed of a slope 82 inclined to an ink discharge port 81 as shown in FIG. 35, in order to discharge ink received by the cap efficiently.
However, in the related art configuration as shown in FIG. 35, of the ink in the concave portion 80a, only the ink just above the ink discharge port 81 is apt to be sucked immediately while the ink far from the ink discharge port 81 is left.